The man, a failed asylum seeker born in the United Arab Emirates (UAE), attacked customers at random on Friday. Police said he acted alone and he was overpowered by passers-by.
The 26-year-old man, identified as Ahmad A, is a Palestinian from the UAE who is registered on an Islamist database, Mr Grote said on Saturday. The attacker, who arrived in Germany in 2015 but could not be deported because he had no identification papers, was also suffering from mental health problems, officials said.
Police have carried out a search of the shelter in Hamburg where the man was living but said there was no evidence that he had accomplices or was part of a terror organisation. It is not yet clear what the suspect’s motivations were.
Police praised the courage of the three men who followed the attacker after video footage emerged of passers-by using chairs as shields to corner the suspect.
Eyewitnesses said that members of the public shouted at the man in Arabic to drop the knife.
A 50-year-old woman and four men aged between 19 and 64 were stabbed, while a 35-year-old man was injured while helping overcome the suspect.
German Chancellor Angela Merkel offered her “deepest sympathies” to the relatives of the murdered victim and praised the courage of the public and the authorities.
“I thank the police for their effort and all those who stood up against the attacker with civil courage and bravery,” Mrs Merkel said, adding that the incident “must and will be fully investigated”.
Germany has suffered a series of attacks in recent months. Security was heightened after a man ploughed a lorry into a busy Christmas market in the heart of Berlin in December 2016. In July 2016, a German teenager of Iranian heritage shot dead nine people in Munich before shooting himself dead.
The same month, a teenage Afghan refugee armed with an axe and a knife injured four people on a train in the southern German city of Wuerzburg before being shot dead by police.